The Government has set up a showdown with the House of Lords over plans for a referendum on changing the voting system for Westminster elections and cutting the number of MPs.
Ministers won votes to overturn defeats inflicted in the upper chamber imposing a turnout threshold on the referendum and allowing greater flexibility over the size of constituencies in the Commons.
MPs also voted to split the Isle of Wight into two separate seats in a concession to peers, who insisted that no MP should represent a seat split between the island and the mainland.
The Parliamentary Voting System and Constituencies Bill endured a troubled passage through the upper chamber, with a procedural crisis as Labour peers were blamed for deliberately slowing its progress.
Opposition to the Bill focused on the attempt to redraw the electoral map to reduce the number of MPs from 650 to 600 with roughly equal numbers of constituents in each seat.
As MPs began their consideration of amendments passed in the Lords, political and constitutional reform minister Mark Harper blamed Labour for deliberately slowing proceedings. He said: "There was an organised filibustering campaign which is unprecedented in the way the other place conducts its business and was of great concern to all those who value the self-regulating nature of the other place."
The Bill needs to clear Parliament before the Lords rises for its half-term recess at the close of Wednesday's business in order for the Electoral Commission to make preparations for a May 5 referendum on adopting the alternative vote (AV) system for Westminster elections. Shadow justice minister Chris Bryant said the Government had "bulldozed" its proposals through.
MPs overturned the Lords amendments which would have given the Boundary Commission the discretion to propose constituencies 7.5% above or below the average size in the event of "exceptional local ties or geographical circumstances".
MPs voted by 317 to 250, majority 67 and 320 votes to 249, majority 71, to disagree with the Lords and restrict variation to 5% above or below the quota. The Lords' attempt to make a referendum binding only if more than 40% of the electorate voted was defeated by 317 votes to 247, Government majority 70.
The Bill will now return to the Lords, where peers could insist on their original changes, leading to a session of parliamentary "ping pong" as the legislation gets passed between the two Houses.